Air cleaner screen



1935 w. H. SCHULZ 2,011,303

AIR CLEANER SCREEN Filed May 14, 1934 3. Sheets-Sheet l bwnvrok William H. Schu/z BY H/s Arroxwzvs Aug. 13, 1935. w. SCHULZ 2,011,303

AIR CLEANER SCREEN Filed May 14, 1934 3 Sheets-Sheet 2 //VI/E/VTOR William H. Schulz BY H/s ATTORNEYS W. H. SCHULZ AIR CLEANER SCREEN Aug. 13, 1935.

FiledMay 14, 3 Sheets-Sheet 5 /NVE NTOE William H. .Schu/z Patented Aug. 13, 1935 UNITED STATES Am CLEANER SCREEN William H. Minneapolis, Minn, assignor to Donaldson Company, Inc., St. Paul, Minn, 1

Milan of Iinnesota Application, 14, 1934, Serial No. 725,515

4 Olnims. V 183-45) My present invention relates to air cleaners for internal combustion engines and the like, and provides an improved screen.

Generally stated, the invention consists of the .5 novel devices, and combinations of devices, ar-

rangement of parts hereinafter described and defined in the claims.

In the accompanying drawings, the improved screen is shown as applied in an air cleaner of the type disclosed and claimed in pending applicatio S. N. 702, 82, filed December 15, 1933, by Wilfred W. Lowther, as inventor, but the screen is applicable to air cleaners of other types. The screen as a product, will appear in the description of u accompanying drawings wherein like characters indicate like parts throughout the several views.

Referring to the drawings:

Fig. l is a plan view with some parts broken away showing a ribbon-like screen section from .0 which a screen element is to be formed;

' Fig. 2 is a perspective showing the screen section as it appears after it has been initially corrugated;

Fig. 3 is a plan view showing the screen after it has been corrugated and the ends thereof connected to, form a drum-like or cylindrical annular structure; t Fig. 4 is a perspective showing a section of the screen as it appears after it has been flattened 80 out to form a flat annular corrugated structure;

Fig. 5 is a plan view with parts broken away showing two of the flat annular screen elements placed together with their corrugations in reverse oblique arrangement;

Fig. 6 is a vertical axial section taken onthe line 6-6 of Fig. 7; andshowingastackorplurality of screen elements placed within an air cleaner of the type shown in the said Lowther application above identified, upper portions of the 40 air cleaner being broken away; and

Fig. '7 is a horizontal section taken on the line 1-1 of Fig. 6-.

The screen element is formed Irom a primarily flat wire screen ribbon 8, the ends of which are I preferably obliquely cut at 9. This screen ribbon is, preferably by suitable corrugating rollers, bent to iorm the same with a plurality of parallel transversely oblique corrugations 8a. 'lhese corrugations 8c are preferably parallel to the oblique ends 9. After the corrugated screen has been formed as shown in Fig. 2, the ends thereof are brought together and rlgidlyconnected by solder orspotweldingsothattherewillbeformeda drum-like or approximately cylindrical annular corrugated structure as shown'in-Pig. 3- mm.

3, the obliqueportions oi the screen are shown in full only in part butit will be understood that that oblique formation will be continued completely around the structure.

After the screen has been formed as shown in Fig. 3, it will be turned into a common plane or to form a flat annular structure. This turning inward of one edge of the structure shown in Fig. 3 to form the structure shown in Figs. 5 and '7, will contract the inner corrugated edge so that E the corrugations will decrease in circumferential spacing and increase in depth in a direction from the perimeter toward the inner edge of the flat annular corrugated element. 7

It is important to note that the corrugations of the screen-are not only transversely oblique to the edges of the screen when bent as shown in Fig. 2, but in the completed screen element will be oblique to radii projected from the axis or center of the screen. Otherwise stated, in the 20 completed element, the corrugations are tangential to'an imaginary circle struck from the axis of the screen and which imaginary circle is not greater but somewhat less than the diameter of the inner edge of the screen. This oblique exten- 5 sion of the corrugations not only facilitates the bending of the screen structure into the flat annular formation but provides an arrangement in which; when several of the said elements are placed one on top of the other in alternately 0 reversed positions, the corrugations of the adjacent screens will contact on transversely intersecting lines so as to prevent nesting oi. the screens even when the screens are made exact duplicates- In Figs. 6 and '7, a stack or multiplicity of the said screens, formed as described, are placed within the shell of the air cleaner. Describin the same-as applied to an air cleaner oi the above identified Lowther type, the numeral ll indicates the outer cylindrical casing, the lower end hr 40 which is primarily open; the numeral ll indicates an oil well telescoped onto the lower end of the casing II and-detachahly held thereto by spring-pressed hooks ii. The numeral l3 indicates an annular battle that surrounds the lower endoianaxialairintaketube llandisshown as held in place by brackets l5.

The operation of the air cleaner with oil intercepiing screens is very fully set forthin the prior Lowther application above identified. For the i0 purposes of this case, it is suiiicient to state that when'the upper portion, not shown, of the casing II is connected to an internal combustion engine, the airwillbe drawn down throughtheaxial air intaketube ",willbedashedagainsttheoilcom been found to be of especially high efiiciency for the purposes had in view, and moreover, they may be made at comparatively small cost and assembled in the most satisfactory manner.

Advisably the screen will be corrugated before the ends thereof have been connected to form an endless drum-like or cylindrical band, but it would be possible to corrugate them after their ends have been united but before the screen has been turned to a flat annular formation.

A screen such as produced by this process can best and most economically be produced by the method or process described, nevertheless, the completed screen, to wit: a corrugated flat annular screen element of thefchara'cter above described, is thought to be broadly new and it is herein claimed as such.

Tests made with air cleaners in which these improved screen elements have been incorporated have shown very high efllciency. This efficiency is due largely to the condensed formation of the inner corrugated portion of the screens. In the operation of the air cleaner such as illustrated in the drawings, for example, the strongest upward current of air and the greatest amount of oil carried by the air will be closely adjacent to the air intake tube l4 and that high velocity air and oil will be carried through the inner portions of the screens or, in other words, through those portions of the screens that have the greatest depth and the most closely spaced corrugations. Otherwise stated, the amount of screen surface condensed in the smaller diameter of the annular screen is equal to that incorporated in the extreme outermost portion of the screen. The condepth and decrease in circumferential spacing in a direction from the perimeter toward the axis of said screen.

2. A screen element'of flat annular formation having transverse corrugations that increase in depth and decrease in circumferential spacing in a direction from the perimeter toward the inner edge of said screen, and which corrugations are oblique to radii projected from the axis of the screen.

3. In an air cleaner, a plurality of screens of the character described in claim 2, in which the screens are assembled in alternately reversed order so that the corrugations thereof contact on intersecting lines.

4. 'In 'an air cleaner, a plurality of disc-like screens having corrugations that are oblique to lines radiating fromthe axes thereof, said screens being assembled in alternately reverse order so that the corrugations thereof extend on intersecting lines.

WILLIAM H. SCHULZ. 

